Orthostannates

Orthostannates are a class of inorganic compounds with the general formula M2SnO4, where M represents a monovalent metal cation. These compounds are characterized by the presence of the orthostannate anion, SnO4^4-. The tin atom in the orthostannate anion is in the +4 oxidation state and is typically coordinated tetrahedrally by oxygen atoms.

These compounds are often prepared by solid-state reactions between metal oxides or carbonates and tin dioxide (stannic oxide) at elevated temperatures. For example, sodium orthostannate (Na2SnO4) can be synthesized by heating sodium carbonate and tin dioxide. The specific structure and properties of orthostannates can vary depending on the nature of the metal cation.

Orthostannates are generally insoluble in water, though some may exhibit slight solubility depending on the cation. Their thermal stability is typically good, and they can decompose at very high temperatures. Applications for orthostannates are relatively limited compared to other tin compounds, but they can be found in some specialized ceramic formulations and as intermediates in the synthesis of other tin-containing materials. Research into their catalytic or electronic properties is ongoing.